Method for controlling growth of microorganisms and/or biofilms in an industrial process

ABSTRACT

The invention relates to a method for controlling of a biofilm, for removing a formed biofilm and/or for controlling a growth of microorganisms, preferably bacteria, in an aqueous environment of an industrial manufacturing process comprising cellulosic fibre material. In the method a composition comprising a compound selected from a group consisting of 3-[(4-methylphenyl)sulphonyl]-2-propenenitrile and 4-amino-N-2-thiazolyl-benzenesulphonamide is administered to the aqueous environment of the process.

FIELD OF INVENTION

The present invention relates to a method for controlling growth ofmicroorganisms and/or biofilms in an industrial process according to thepreamble of the enclosed independent claim.

BACKGROUND OF THE INVENTION

Microorganisms are present in most of the industrial processes. Theirpresence is especially cumbersome in processes which are waterintensive, such as manufacture of pulp, paper, board or the like.Microorganisms thrive when the process water contains biodegradabledissolved substances, and the temperature and pH of the process waterare favourable for microbial life. Microorganisms may enter the processthrough contamination from air, incoming raw water and/or non-sterileraw materials. If no countermeasures are taken, microorganisms may causeextensive problems in a process, such as papermaking. Problems relatedto microorganisms include, for example, decomposition of chemicaladditives, detrimental change in process pH, formation of malodorous ortoxic compounds, and/or biofilm formation on surfaces.

In manufacture of paper and board the problems may lead to defects, suchas spots and holes, in the formed web, or even to web breaks and machinestops, for example when slime slumps are sloughing off. In a pulp, paperor board mill uncontrolled microbial growth could thus cause problemsand there is a need for effective microbial control treatment. However,only limited number of antimicrobial agents demonstrates good biocidalperformance at the process conditions prevailing in a paper or boardmanufacture, e.g., high content of cellulosic fibre material, hightemperature, high flow rates and high oxidizer demand. Furthermore, inthese processes the microorganisms, mainly bacteria, are continuouslypresent and may be introduced in the middle of the continuous process.Due to the process conditions the conventional biocides, which are usedin pulp, paper and board industry are different from commonantimicrobial agents used in other industries, e.g., food industry or inagriculture. For example, in food industry the environment is sterilizedin the beginning whereafter the production continues under sterileconditions and sterile raw materials. These conditions are verydifferent from the non-sterile conditions prevailing in an open paper orboard production process. Especially important in processes comprisingcellulosic fibre material, such as pulp, paper and board manufacture, isthe effective control of biofilm on the process surfaces. Biofilmformation is still a frequent problem in manufacture of paper and board,despite the regular use of common biocides in the recirculating waterflows. There is a need to improve efficacy of biofilm control underconditions of pulp, paper and board making processes.

SUMMARY OF THE INVENTION

An object of this invention is to minimise or possibly even eliminatethe disadvantages existing in the prior art.

Another object of the present invention is to provide a method whichmakes it possible to effectively control biofilms with a low dosage inan industrial manufacturing process comprising cellulosic fibrematerial, for example, in pulp, paper or board manufacture.

An object of the present invention is to provide a method which makes itpossible to effectively prevent, inhibit and/or reduce biofilm growthwith a low dosage in an industrial manufacturing process comprisingcellulosic fibre material, for example, in pulp, paper or boardmanufacture.

An object of the present invention is to provide a method which makes itpossible to effectively control the growth of microorganisms in anindustrial manufacturing process comprising cellulosic fibre material,for example, in pulp, paper or board manufacture.

Yet another object of the present invention is to provide simple andeffective method for industrial biofilm control at high temperatures,especially in aqueous process conditions with high cellulosic fibrecontent and/or at least locally high shear forces and/or high flowrates.

These objects are attained with the invention having the characteristicspresented below in the characterising parts of the independent claims.

Some preferred embodiments of the invention are presented in thedependent claims.

The embodiments mentioned in this text relate, where applicable, to allaspects of the invention, even if this is not always separatelymentioned.

In a typical method according to the present invention for controllingbiofilm and/or for removing of a formed biofilm and/or for controlling agrowth of microorganisms, preferably bacteria, in an aqueous environmentof an industrial manufacturing process comprising cellulosic fibrematerial, by administering to the aqueous environment of the process acomposition comprising a compound selected from group consisting of3-[(4-methylphenyl)sulphonyl]-2-propenenitrile and4-amino-N-2-thiazolyl-benzenesulphonamide.

Now it has been found that the compounds selected from3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide are highly effective incontrolling the formation of biofilm and/or growth of microorganisms, inan aqueous environment of an industrial manufacturing process comprisingcellulosic fibre material, especially in paper, board and pulpmanufacture. The obtained effect is good even at low dosage of thecompound and in aqueous environments having high flow rate and/or hightemperature. It was unexpected that the compounds would showantimicrobial performance that is as good as or even better than theconventional antimicrobial agents used in pulp and paper industryagainst biofilms. The compositions of the invention are useful inproviding an anti-bacterial effect and controlling the growth of biofilmand/or bacteria.

In the present context of the term “controlling of biofilm growth”encompasses control actions selected at least from preventing,inhibiting and/or reducing of biofilm. These control actions may takeplace before, during or after biofilm formation and the control actionsmay take place separately or simultaneously, for example compositionscomprising said compounds may both prevent formation of new biofilm andsimultaneously reduce the existing biofilm. The compounds may be usefulin preventing of biofilm. This means that the compounds preventformation of biofilm on bio-film free process surfaces. The compoundsmay also be useful in inhibiting of biofilm. This means that thecompounds inhibit further growth of existing biofilm and/or inhibitformation of biofilm on a biofilm free process surface. The compoundsmay further be useful in reducing the biofilm. This means that thecompounds reduce the amount of existing biofilm on the process surfaces.In general, control of biofilm growth may be achieved by controlling theamount of microorganisms in the process and/or by controlling theirgrowth in biofilm mode. The composition comprising said compounds may beuseful in controlling the growth of microorganisms, either in biofilmand/or free in the aqueous environment of an industrial manufacturingprocess comprising cellulosic fibre material, preferably in biofilm.

In the present context the term “biofilm” is understood as a communityof microorganisms, typically bacteria, which adheres to a processsurface and usually grows surrounded by a complex matrix of extrapolymeric substances. The biofilm protects the microorganisms, whichmakes the control of biofilm growth more challenging than control ofgrowth of free microorganisms. Ineffective biofilm control may causesignificant issues in industrial processes, for example in form ofincreased cleaning need, production stops and/or deterioration ofproduction quality and/or quantity.

In the present context the term “controlling of the growth of themicroorganisms” refers to eliminating and/or reducing of the amountand/or activity of microorganisms and the term is synonymous to anybiostatic or biocidal effect, such as killing, preventing, removing, orinhibiting the growth of microorganisms. The microorganisms may bepresent in free form in the aqueous environment or in a form of abiofilm, known also as biofilm mode of growth

In the present context the term “aqueous environment” refers to anindustrial water system, containing aqueous solution. The presentinvention relates especially to industrial processes having an aqueousenvironment comprising cellulosic fibre material of natural origin.

According to one embodiment of the invention the temperature of theaqueous environment is at least 40° C., preferably at least 50° C.

Especially the composition of the present invention is suitable foradministering or use in industrial manufacturing processes comprisingcellulosic fibre material, such as manufacture of paper, board, pulp,tissue, moulded pulp, non-woven, viscose or the like. The aqueousenvironment comprises preferably at least water, cellulosic fibrematerial, fines and/or fibre fragments of natural origin. The aqueousenvironment may also comprise starch. The cellulosic fibre materialpreferably originates from softwood, hardwood or non-wood sources, suchas bamboo or kenaf, or any mixtures thereof. Preferably the cellulosicfibre material originates from lignocellulosic fibre material. Morepreferably the cellulosic fibre material is lignocellulosic fibres. Thecellulosic fibre material may originate from any suitable mechanical,chemi-mechanical or chemical pulping process or any of theircombinations or any other suitable pulping process known as such. Thecellulosic fibre material may also comprise fibre material whichoriginates from recycled board, paper or pulp. For example, thecellulosic fibre material may comprise cellulosic fibres that originatefrom hardwood and have a length of 0.5-1.5 mm and/or from softwood andhave a length of 2.5-7.5 mm. The aqueous environment may also compriseinorganic mineral particles, such as fillers and/or coating minerals;hemicelluloses; lignin; and/or dissolved and colloidal substances. Theaqueous environment may also comprise papermaking additives, such asstarch, sizing agents, inorganic or organic coagulation or flocculationagents, natural or synthetic polymers of different length and/or charge,dyes, optical brighteners, or any combination thereof.

The composition may comprise the compound3-[(4-methylphenyl)sulphonyl]-2-propenenitrile in form of a Z- orE-isomer, or the composition may comprise a mixture of both isomers. Forexample, the ratio of E to Z isomers in the composition may be from70:30 to 100:0 or from 80:20 to 99:1. Alternatively the ratio of E to Zisomers in the composition may be from 30:70 to 0:100 or from 20:80 to1:99

According to one embodiment of the invention it is possible toadminister to the industrial manufacturing processes comprisingcellulosic fibre material a composition comprising one or both of thecompounds selected from 3-[(4-methylphenyl)sulphonyl]-2-propenenitrileand 4-amino-N-2-thiazolyl-benzenesulphonamide. In case both compoundsare administered to the aqueous environment, they may be administered asone composition, i.e., a mixture, or they may be administered as twodifferent compositions successively after each other. In case bothcompounds are administered, the individual dosages for both compoundsmay be the same or different from each other. In this manner it ispossible to effectively control the biofilm and/or microorganisms in theaqueous environment.

The present invention is suitable for controlling the growth ofmicroorganisms, such as bacteria, belonging to genus of Meiothermus,Deinococcus and/or Pseudoxanthomonas in the aqueous environment.According to one embodiment of the invention the aqueous environment ofthe industrial manufacturing process comprising cellulosic fibrematerial thus comprises bacteria belonging to genus of Meiothermus,Deinococcus and/or Pseudoxanthomonas, either alone or in anycombination, or the aqueous environment is in contact with a biofilm atleast partially formed by any of the said bacteria. The microorganismsin the said industrial processes are typically not photosyntheticmicroorganisms, i.e., preferably the aqueous environment is almost orcompletely free of photosynthetic microorganisms, e.g. algae. Additionof the compound selected from3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide reduces the amount of the saidmicroorganisms, either in free form or as biofilm, or even eliminatestheir presence in the aqueous environment completely. The eliminationmay be total or partial. The prevention refers here to any preventiveeliminating action which reduces or inhibits the growth of themicroorganisms in biofilm mode and thereby totally or partially preventsthe formation of the biofilm.

In general, the composition comprising the compound selected from3-[(4-methylphenyl)-sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide may be added to the aqueousenvironment in biostatic or biocidal amounts. Biostatic amount refers toan amount sufficient to at least prevent and/or inhibit the activityand/or growth of the microorganisms or the biofilm. Biocidal amountrefers to more effective activity, such as to an amount capable ofreducing the activity and/or growth of the microorganisms or the biofilmand/or killing most or all of the microorganisms present in the aqueousenvironment. According to one embodiment of the invention the compoundmay be added to the aqueous environment in dosage amount of 0.01-100ppm, preferably 0.01-10 ppm, more preferably 0.01-2 ppm or 0.01-1 ppm,even more preferably 0.01-0.5 ppm or 0.01-0.3 ppm, calculated as activeingredient, i.e., 3-[(4-methylphenyl)sulphonyl]-2-propenenitrile and/or4-amino-N-2-thiazolyl-benzenesulphonamide. The effectiveness of thecompound enables the use of low dosages and low concentrations whilemaintaining good control of micro-organisms growth and biofilm formationand/or growth.

Compositions comprising compounds selected from3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide may be added to the aqueousenvironment as a solid, such as dry powder, or more preferably in aliquid form. Compounds may be dosed continuously or periodically.According to one embodiment of the invention the compounds may beadministered periodically in the aqueous environment for 3-45 minutesfor 6-24 times a day, preferably for 10-30 minutes for 12-24 times aday.

According to one embodiment of the invention the industrialmanufacturing process having an aqueous environment comprisingcellulosic fibre material of natural origin is pulp and/or paper and/orboard manufacturing process, where the aqueous environment shows hightemperature and/or high flow rate. The compound selected from3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide is thus added or dosed to apulp and/or paper and/or board manufacturing system. The aqueousenvironments in these processes often show high flow and high shearrates, which may induce the formation of biofilm on the process surfacesdue to the stress of microorganisms. For example, paper and board makingenvironments the flow rates may typically be higher than 1 m/s, evenover 10 m/s, typically from 1 to 20 m/s or from 1 to 10 m/s. It has beenobserved that the compositions comprising the said compounds areeffective especially in these demanding conditions, and it may begenerally used throughout the whole process in order to reduce and/or toprevent the growth of microorganisms and the formation of biofilm on theprocess surfaces. In principle, compositions comprising said compoundsmay be added at almost any point in the process, especially into processwith recirculated process water to maintain the control ofmicroorganisms and/or biofilm formation throughout the process. Thecompositions comprising the said compounds may also or alternatively beadded to the cellulosic fibre material, e.g., lignocellulosic fibrematerial, which is used as a raw material in the process.

The industrial manufacturing process having an aqueous environmentcomprising cellulosic fibre material of natural origin may be pulpand/or paper and/or board manufacturing process, where the pH of theaqueous environment is in the range 5-9, preferably 7-8.5.

According to one preferable embodiment of the present invention thecompound selected from 3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide may be added in the industrialmanufacturing process having an aqueous environment comprisingcellulosic fibre material, which is paper and/or board manufacturingprocess, especially in a short loop of the paper or board makingprocess. In a typical paper and board making process, pulp stock ispassed into a headbox, which distributes the pulp stock onto a movingwire in a forming section, on which the continuous paper web is formed.The short loop or short circulation section of a paper/board machine ishere understood, as customary in the art, the part of the manufacturingsystem that re-circulates and recycles at least a part of excess waterfrom the pulp stock, collected in a wire pit in the forming section,back to the headbox for re-use.

Alternatively, or in addition, the compound selected from3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide may be added in the industrialmanufacturing process having an aqueous environment comprisingcellulosic fibre material, e.g. pulp and/or paper and/or boardmanufacturing process, to process water storage towers, such ascirculating water towers and filtrate water towers; to clear or cloudyfiltrate storage tanks; pulpers; aqueous streams upstream/downstream ofthe pulpers; broke system and aqueous process streamsupstream/downstream of vessels therein; wire pit process streamsupstream/downstream of the pit; paper machine blend chest processstreams up-stream/downstream of the chest; fresh water tank; warm watertank and/or shower water tank.

Alternatively, or in addition, the compound selected from3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide may be added in the industrialmanufacturing process having an aqueous environment comprisingcellulosic fibre material, which is paper and/or board manufacturingprocess, to any location in a long loop of the paper or board makingprocess. The long loop or long circulation section of a paper/boardmachine is here understood, as customary in the art, the part of themanufacturing system that handles excess water and broke. Major part ofthe recovered water exit the short loop and is pumped to long loop,which includes: save-all for capturing useful fibres from the recoveredwater for reuse, storage tanks for filtrate water used for example inmachine showers, and storage tanks for recirculated water used forexample as dilution water for importing pulp from pulp mill topaper/board machine. A part of the long loop is the broke system forhandling of wet and dry paper rejects from the machine. This material isrepulped and reused as a part of the pulp stock.

According to one embodiment the compound selected from3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide is added to aqueousenvironment, which comprises a residual of peroxide from about 0.01 toabout 100 ppm or from about 0.01 to about 50 ppm.

According to one embodiment of the invention the compound selected from3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide may be used in combinationwith other biocidal or antimicrobial agents. Suitable other biocidal orantimicrobial agents can be non-oxidizing biocidal or antimicrobialagents, or oxidizing biocidal or antimicrobial agents. Suitablenon-oxidizing biocidal or antimicrobial agents are, for example,glutaraldehyde, 2,2-dibromo-3-nitrilopropionamide (DBNPA),2-bromo-2-nitropropane-1,3-diol (Bronopol), quaternary ammoniumcompounds, carbamates, 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT),and 2-methyl-4-isothiazolin-3-one (MIT). Suitable oxidizing biocidal orantimicrobial agents are, for example, chlorine, salts of hypochlorite,hypochlorous acid, chlorinated isocyanurates, bromine, salts ofhypobromite, hypobromous acid, bromine chloride, chlorine dioxide,ozone, hydrogen peroxide, and peroxy compounds, such as peracetic acidor performic acid. Other suitable oxidizing biocidal agents are, forexample, stabilized halogen compounds wherein active halogen, such aschlorine or bromine is reacted with a nitrogenous compound, such asdimethylhydantontoin, an ammonium salt, urea, carbamate, or anothernitrogen containing molecule capable of reacting with active halogen.For example, in one embodiment the compound selected from3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or4-amino-N-2-thiazolyl-benzenesulphonamide is added to aqueousenvironment, which comprises a residual of active halogen in the rangefrom about 0.01 to about 20 ppm, given as active chlorine.

DETAILED DESCRIPTION OF THE INVENTION

Some embodiments of the invention are described more closely in thefollowing non-limiting examples.

Materials and Methods used in the Examples

Pure cultures of Meiothermus silvanus, a microbe species commonly foundin paper machine biofilms (Ekman J, Journal of Industrial Microbiology &Biotechnology 34:203-211) and Pseudoxanthomonas taiwanensis, anotherspecies commonly found in paper machine environments (Desjardins, E &Beaulieu, C, Journal of Industrial Microbiology & Biotechnology30:141-145) were used to study the efficacy of various chemicals toprevent biofilm formation.

Biofilm tests were done in either synthetic commercial R2-broth (Lab MLtd, UK) or fibre-containing synthetic paper machine water, SPW(prepared according to Peltola et al., J. Ind. Microbiol. Biotechnol.2011, 38: 1719-1727) using 96-microwell plate wells with peg lids(Thermo Fischer Scientific Inc., USA). Plates were incubated at 45° C.with a rotary shaking (150 rpm) providing high flow in each well.

3-[(4-methylphenyl)sulfonyl]-2-propenenitrile, hereinafter calledCompound A, was obtained from EMD Biosciences Inc, USA; purity ≥98%E-isomer.

4-amino-N-2-thiazolyl-benzenesulphonamide, hereinafter called CompoundB, was obtained from Sigma Aldrich Finland Oy.

2,2-dibromo-3-nitrilopropionamide, hereinafter called DBNPA, wasobtained from Kemira Oyj (Fennosan R20, 20% active ingredient).

Test Method for Prevention of Biofilm Formation

For experiments of preventing biofilm formation wells of 96-microwellplates with peg-lids were filled with R2-broth or SPW, inoculated withthe pure bacterial cultures and treated with different amounts ofchemical compounds to be tested. Peg-lid was put on. After 24 hours thewells were emptied and a fresh solution of pure culture containing SPWor R2 broth with different amounts of test chemicals were added to thewells and the original peg-lid was put back in place. After anadditional 24 hours, i.e., 48 hours after starting the test, the wellswere emptied, rinsed and the peg lid and wells were left to dry.

Test Method for Removal of Existing Biofilm

For experiments of removing already existing (preformed) biofilm wellsof 96-microwell plates with peg-lids were filled with SPW, inoculatedwith the pure bacterial cultures. Biofilm was grown for 24 hours withoutaddition of any chemical compound to be tested. In some experimentsafter 24 hours the procedure was repeated by emptying the wells and byaddition of a fresh solution of SPW inoculated with pure bacterialculture, again without any test chemical compound. The original peg-lidwas put back in place and biofilm was allowed to grow for additional 24h, i.e., in total 48 h.

After 24 or 48 hours after starting the test, the wells were emptied anda fresh solution of SPW, inoculated with the pure bacterial cultures andwith different amounts of chemical compounds to be tested were added andthe original peg-lid was placed back in place. After an additional 2 or24 hours the wells were emptied, rinsed and the peg lid and wells wereleft to dry.

Quantification of Formed Biofilm

The amount of biofilm formed on the microwells, and peg surfaces wasquantified with a staining solution by adding 200 μl of 1% CrystalViolet (Merck Millipore KGaA, Germany) in methanol to each well andplacing the peg-lid back on. After 3 minutes the wells were emptied, andthe wells and pegs were rinsed 3 times with tap water. The attachedCrystal Violet was dissolved into ethanol and the absorbance at 595 nmwas measured. The values shown in the following tables are averageabsorbance from 8 replicate wells and pegs.

All absorbance values in Examples 1-6 are given actual measured values.In calculation for biofilm reduction percentages it was taken in accountthat the SPW alone for 2 days without any bacterial inoculum gave abackground value of 0.14.

Example 1

Tables 1 and 2 demonstrate the ability of Compound A to prevent biofilmformation of Meiothermus silvanus and Pseudoxanthomonas taiwanensis.Test conditions simulated paper or board making process conditions(synthetic paper machine water, high temperature, fibres present, highflow) and Compound A was observed to control biofilms at a very lowconcentration. Already a dosage of 0.13 mg/l active Compound A gave over90% biofilm reduction effect. For comparison, the conventionalantimicrobial agent DBNPA required a dosage of 1 mg/l active compound toreach same biofilm reduction efficacy. The results for DBNPA are givenin Tables 3 and 4.

Table 1 shows the effect of Compound A dosing to Meiothermus silvanusbiofilms in SPW at 45° C. and 150 rpm (high mixing). Biofilm was stainedand quantified by absorbance measurement. Dosage given as activeingredient.

TABLE 1 Dosage of Compound A Biofilm quantity after 48 h contact time[mg/l] Abs. at 595 nm Biofilm reduction [%] 0 0.98 — 0.01 0.80 21.4 0.030.75 27.4 0.08 0.58 47.6 0.13 0.22 90.5 0.20 0.15 98.8

Table 2 shows the effect of Compound A dosing to Pseudoxanthomonastaiwanensis biofilms in SPW at 45° C. and 150 rpm (high mixing). Biofilmwas stained and quantified by absorbance measurement. Dosage given asactive ingredient.

TABLE 2 Dosageof Compound A Biofilm quantity after 48 h contact time[mg/l] Abs. at 595 nm Biofilm reduction [%] 0 1.48 — 0.01 1.42 4.5 0.031.26 16.4 0.08 0.88 44.8 0.13 0.55 69.4 0.20 0.39 81.3

Table 3 shows the effect of DPNPA dosing to Meiothermus silvanusbiofilms in SPW at 45° C. and 150 rpm (high mixing). Biofilm was stainedand quantified by absorbance measurement. Dosage given as activeingredient.

TABLE 3 Dosage of DBNPA Biofilm quantity after 48 h contact time [mg/l]Abs. at 595 nm Biofilm reduction [%] 0 0.66 0.2 0.57 16.9 0.6 0.35 60.71 0.15 98.8

Table 4 shows the effect of DPNPA dosing to Pseudoxanthomonastaiwanensis biofilms in SPW at 45° C. and 150 rpm (high mixing). Biofilmwas stained and quantified by absorbance measurement. Dosage given asactive ingredient.

TABLE 4 Dosage of DBNPA Biofilm quantity after 48 h contact time [mg/l]Abs. at 595 nm Biofilm reduction, [%] 0 1.65 0.2 1.46 12.6 0.6 1.23 27.81 0.14 99.9

Results in Tables 1-4 demonstrate that Compound A is capable to preventbiofilm formation of dominant industrial biofilm-formers under papermachine conditions at a very low dosage when compared to conventionalbiocide used in paper industry.

Example 2 (Reference)

Tables 5 and 6 show effect of a well-known antibiotic Gramicidin againstbiofilm formation of Meiothermus silvanus and Pseudoxanthomonastaiwanensis. In a synthetic growth medium R2-broth Gramicidin wascapable to prevent biofilm formation at clearly lower concentration thanin conditions simulating paper or board making process (synthetic papermachine water, high temperature, fibres present, high flow).

The results in Table 5 and 6 demonstrate expected behaviour of aclinical antimicrobial compound with deteriorating performance whenexposed to non-clinical conditions. In contrary, Compound A was capableto control biofilms in paper machine water at a very low concentrationas shown in Example 1.

Table 5 shows the effect of Gramicidin dosing to Meiothermus silvanusbiofilms in R2-broth and SPW. Biofilm was stained and quantified byabsorbance measurement. Dosage given as active ingredient.

TABLE 5 Biofilm quantity Biofilm quantity after after 48 h 48 h contactcontact time time in SPW Dosage of in R2-broth Biofilm Gramicidin Abs.at 595 Biofilm reduction, [mg/l] nm reduction, [%] Abs. at 595 nm f%] 01.60 — 1.36 0.2 1.40 13.7 1.33 2.5 1 0.66 64.4 1.41 −4.1 3 0.17 97.90.45 74.6 10 0.14 100.0 0.19 95.9

Table 6 shows the effect of Gramicidin dosing to Pseudoxanthomonastaiwanensis biofilms in R2-broth and SPW. Biofilm was stained andquantified by absorbance measurement. Dosage given as active ingredient.

TABLE 6 Biofilm quantity Biofilm quantity after 48 h after 48 h contactcontact time in time in SPW Dosage of R2-broth Biofilm Gramicidin Abs.at 595 Biofilm reduction, [mg/l] nm reduction, [%] Abs at 595 nm f%] 02.78 — 2.37 3 2.80 −0.8 2.25 5.4 10 2.55 8.7 2.41 −1.8 25 0.19 98.1 2.42−2.2

Example 3

Tables 7 and 8 demonstrate the ability of Compound B to prevent biofilmformation of Meiothermus silvanus and Pseudoxanthomonas taiwanensis.Test conditions are identical to test conditions of Example 1.

Table 7 shows the effect of Compound B dosing to Meiothermus silvanusbiofilms in SPW at 45° C. and 150 rpm (high mixing). Biofilm was stainedand quantified by absorbance measurement. Dosage given as activeingredient.

TABLE 7 Dosage of Compound B Biofilm quantity after 48 h contact time[mg/l] Abs. at 595 nm Biofilm reduction [%] 0 0.88 0.1 0.62 34.4 0.250.18 94.0 1 0.15 99.1 3 0.16 97.9 10 0.18 94.0

Table 8 shows the effect of Compound B dosing to Pseudoxanthomonastaiwanensis biofilms in SPW at 45° C. and 150 rpm (high mixing). Biofilmwas stained and quantified by absorbance measurement. Dosage given asactive ingredient.

TABLE 8 Dosage of Compound B Biofilm quantity after 48 h contact time[mg/l] Abs. at 595 nm Biofilm reduction [%] 0 2.41 0.25 2.35 2.6 1 2.0416.3 3 0.84 69.3 10 0.54 82.4

Results in Tables 7 and 8 demonstrate that Compound B can preventbiofilm formation of dominant industrial biofilm-formers under papermachine conditions.

Example 4

Tables 9 and 10 demonstrate the ability of Compound A to remove alreadyformed biofilm of Meiothermus silvanus and Pseudoxanthomonastaiwanensis. Test conditions simulated paper making process conditions(synthetic paper machine water, high temperature, fibres present, highflow). Compound A was observed to remove already formed biofilms. Asingle dosage of 0.5 mg/l active compound removed all of the biofilmformed during the 48-hour pre-growth time in 24 hours after addition ofCompound A.

Table 9 shows the effect of Compound A dosage to Pseudoxanthomonastaiwanensis biofilms in SPW at 45° C. and 150 rpm (high mixing). Biofilmwas pre-grown for 48 h after which Compound A was added in given amount.After 24 hours the biofilm was stained and quantified by absorbancemeasurement. Compound A dosage is given as active compound.

TABLE 9 Dosage of Biofilm quantity after 48 h pre-growth Compound A and24 h contact time [mg/l] Abs. at 595 nm Biofilm reduction [%] 0 2.48 0.21.73 32.2 0.5 0.13 100.2

Table 10 shows the effect of Compound A dosing to Meiothermus silvanusbiofilms in SPW at 45° C. and 150 rpm (high mixing). Biofilm waspre-grown for 48 h after which Compound

A was added in given amount. After 2 hours the biofilm was stained andquantified by absorbance measurement. Compound A dosage is given asactive compound.

TABLE 10 Dosage of Biofilm quantity after 48 h pre-growth Compound A and2 h contact time [mg/l] Abs. at 595 nm Biofilm reduction [%] 0 1.30 0.51.20 8.0 1 1.11 16.3 2 0.99 26.6

Example 5

Compound A was obtained and its E- and Z-isomers were separated fromeach other. Tables 11 and 12 demonstrate the ability of E- and Z-isomersof Compound A to prevent biofilm formation of Meiothermus silvanus andPseudoxanthomonas taiwanensis. Test conditions are identical to testconditions of Example 1. It is seen that both isomers of Compound Aprevent biofilm formation.

Table 11 shows the effect of E-and Z-isomers of Compound A toMeiothermus silvanus biofilms in SPW at 45° C. and 150 rpm (highmixing). Biofilm was stained and quantified by absorbance measurement.Compound A dosage is given as active compound.

TABLE 11 Biofilm quantity Biofilm quantity after 48 h contact after 48 hcontact time, E-isomer time Z-isomer Dosage of Biofilm Biofilm CompoundA Abs. at reduction Abs. at reduction [mg/l] 595 nm [%] 595 nm [%] 01.52 — 1.52 — 0.1 0.40 88.9 0.16 99.1 0.2 0.16 99.3 0.15 99.4

Table 12 shows the effect of E- and Z-isomers of Compound A toPseudoxanthomonas taiwanensis biofilms in SPW at 45 ° C. and 150 rpm(high mixing). Biofilm was stained and quantified by absorbancemeasurement. Compound A dosage is given as active compound.

TABLE 12 Biofilm quantity after 48 h Biofilm quantity after 48 h contacttime, E-isomer contact time, Z-isomer Dosage of Biofilm Biofilm CompoundA reduction reduction [mg/l] Abs. at 595 nm [%] Abs. at 595 nm [%] 01.46 — 1.46 — 0.1 0.36 90.6 0.16 99.3 0.2 0.16 99.1 0.16 99.3

Example 6

Compound A was obtained and its E- and Z-isomers were separated fromeach other. Table 13 demonstrates the ability E- and Z-isomers ofCompound A to remove already formed biofilms of Meiothermus silvanus andPseudoxanthomonas taiwanensis. Test conditions simulated paper makingprocess conditions (synthetic paper machine water, high temperature,fibres present, high flow). It is seen that both isomers of Compound Aare effective in removing of already formed biofilms.

Table 13 shows the effect of E- and Z-isomers of Compound A toMeiothermus silvanus biofilms in SPW at 45° C. and 150 rpm (highmixing). Biofilm was pre-grown for 24 h after E- or Z-isomer of CompoundA was added in amount indicated. After 24 hours the biofilm was stainedand quantified by absorbance measurement. Compound A dosage is given asactive compound.

TABLE 13 Biofilm quantity after Biofilm quantity after 24 h pre-growth24 h pre-growth and 24 h contact time, and 24 h contact time, Dosage ofE-isomer Z-isomer Compound A Abs. at Biofilm Abs. at Biofilm [mg/l] 595nm reduction [%] 595 nm reduction [%] 0 1.36 — — — 0.2 0.90 67.6 0.8171.3 1 0.26 95.0 0.27 94.6

Even if the invention was described with reference to what at presentseems to be the most practical and preferred embodiments, it isappreciated that the invention shall not be limited to the embodimentsdescribed above, but the invention is intended to cover also differentmodifications and equivalent technical solutions within the scope of theenclosed claims.

What is claimed is:
 1. A method to control formation of a biofilm in anaqueous industrial manufacturing environment comprising cellulosicfibers and having a temperature of at least 40° C., the methodcomprising a step of adding a composition comprising3-[(4-methylphenyl)sulphonyl]-2-propenenitrile as an active compound. 2.The method of claim 1, wherein controlling formation of a biofilmcomprises reducing growth of the biofilm and/or removing an existingbiofilm.
 3. The method according to claim 1, wherein the aqueousindustrial manufacturing environment is an aqueous environment inmanufacturing paper, board, pulp, tissue, moulded pulp, or non-woven orviscose.
 4. The method according to claim 3, wherein the cellulosicfibres are lignocellulosic fibres.
 5. The method of claim 3, wherein theaqueous environment comprises starch, inorganic mineral particles inform of fillers and/3 or paper coating materials, hemicelluloses, ligninand/or dissolved and colloidal substance.
 6. The method of claim 1.wherein the composition is administered to the aqueous environment in anamount of 0.01-100 ppm of the active compound.
 7. The method of claim 6,wherein the composition is administered in an amount of 0.01-10 ppm ofthe active compound.
 8. The method according to claim 7, wherein thecomposition is administered in an amount of 0.01- 2 ppm of the activecompound.
 9. The method according to claim 8, wherein the composition isadministered to the aqueous environment in an amount of 0.01-1 ppm ofthe active compound.
 10. The method according to claim 9, wherein thecomposition is administered in an amount of 0.01-0.5 ppm the activecompound.
 11. The method according to claim 10, wherein the compositionis administered in an amount of 0.01-0.3 ppm of the active compound. 12.The method according to claim 3, wherein the aqueous environmentcomprises a residual of peroxide from about 0.01 to about 100 ppm. 13.The method according to claim 3, wherein the aqueous environmentcomprises a residual of active halogen in the range from about 0.01 toabout 20 ppm, given as active chlorine.
 14. The method according toclaim 1, wherein the composition is administered periodically in theaqueous environment for 3-45 minutes for 6-24 times a day.
 15. Themethod according to claim 14, wherein the composition is administeredperiodically in the aqueous environment for 10-30 minutes for 12-24times a day.
 16. The method according to claim 1, wherein thecomposition is added in addition to other biocidal or antimicrobialagents.